The present invention relates to a head-down type optical device designed to deliver information to the driver of a motor vehicle.
Numerous devices have already been proposed for delivering optical information to the driver of a motor vehicle. For example, indicator lamps and instruments having moving pointers have been in use for a long time. More recently, light-emitting displays and liquid crystal displays have been proposed.
These tend to be preferred nowadays, in particular for reasons of appearance. However, their cost is often prohibitive when the display is to be large in size.
Systems of the so-called "head-down display" type are known in the field of aviation. The purpose of these systems is to project information to infinity or to a great distance in an equipment field of view situated immediately below the bottom line of view in the landscape field of view, without superposing information on the landscape. "Head-down display" type systems make it possible to acquire the projected information appreciably more quickly since they limit the accommodation or convergence that is required when passing from landscape to information.
However, the head-down type systems proposed for aviation are generally complex and expensive.
Proposals have also been made, for example in Document WO-A-8902611 for head-down type display systems that provide information to the driver of a motor vehicle.
However, the system described in Document WO-A-8902611 is also quite complex. In particular, it comprises a display associated with a source of illumination by means of a bundle of optical fibers.
The system described in Document WO-A-8902611 has not, as yet, given rise to an application in the field of motor vehicles.